1960-2012年中国天山山区极端气温的变化特征

Changes of Extreme Temperature Events in the Chinese Tianshan Mountains During the Perod from 1960 to 2012

根据1960—2012年天山山区海拔1 500m以上的8个气象站点逐日最高、最低气温资料,利用线性倾向估计法、Morlet小波分析、主成分分析法和相关分析等方法研究了该地区9个极端气温指标的时间变化趋势和空间分布规律。结果表明:(1)冷昼日数、冷夜日数、冰冻日数、霜冻日数、冷持续日数分别以-0.70,-2.36,-1.00,-5.14,-1.12d/10a的趋势减小,而暖昼日数、暖夜日数、生物生长季分别以0.87,2.70,4.03d/10a的趋势增加,气温日较差的年际倾向率为-0.34d/10a;(2)暖昼(夜)日数的变暖幅度大于冷昼(夜)日数;(3)从空间分布来看,极端气温增加或减少的趋势表现出明显空间差异;(4)天山山区近53a来各极端气温指数都在一定的时间序列中存在不同的周期变化,周期变化明显;(5)因子分析的结果表明,除了气温日较差外,各极端气温指数之间均呈现出很好的相关性。

Based on daily maximum and minimum temperature at 8 meteorological stations above 1 500 m in the Chinese Tianshan Mountains observed by the China Meteorological Administration from 1960 to 2012, the spatial and temporal variation characteristics of extreme temperature events were analyzed by the methods of linear regression, Mann-Kendall, Morlet wavelet, factor analysis and correlation analysis. Nine indices of extreme temperature were studied. The results are as follows. （1） The occurrence of cold days, cold nights, ice days, frost days and extreme cold days have significantly decreased by --0.70, --2.36, --1.00, --5.14, --1. 12 days/decade, respectively. Meanwhile, the occurrence of warm days, warm nights and growing season length show significant increase at rates of 0.87, 2.70, 4.03 days/decade, respectively; the tendency rate of diurnal temperature range is --0.34 days/decade, respectively. （2） The warming trend of warm night is significantly larger than cold night, and the warming trend of warm （cold） night days are obviously larger than the warm （cold） days. （3） From the point of spatial distribution, the increase or decrease trend of extreme temperature shows obvious difference. （4） Each extreme temperature index in Tianshan Mountain from 53 a shows significantly different periodicity change in certain time series. （5） The factor analysis demonstrates that the extreme temperature indices are closely correlated with each other except diurnal temperature range.